Qns about DCS

[dive_lover88]

I've these questions that i want to ask.

Is it possible that a person who get DCS/DCI but doesnt know it? Will the excess nitrogen keep circulating around the body and will there be any longterm effect on that person?

 

[Kendall Raine]

I've these questions that i want to ask.

Is it possible that a person who get DCS/DCI but doesnt know it? Will the excess nitrogen keep circulating around the body and will there be any longterm effect on that person?

Really good question. Clinical DCS means there are symptoms. One can deny those symptoms are due to DCS, but that doesn't change their origin. In some cases even experts will disagree whether a particular symptom is caused by DCS or something else. So yes, it is possible to have DCS and not know definitively whether what you're experiencing is due to DCS or something else.

There is another grouping of diving related issues termed sub-clinical DCS. These don't produce frank DCS symptoms. These can be transitory generalized symptoms, like fatigue or flu like symptoms, or be long term and asymptomatic, like bone necrosis, brain stem lesions, retinal issues and higher mental function impairment caused by asymptomatic inert gas blood flow problems. The causes, and implications, of the sub-clinical stuff is very much the subject of debate and some, although, not a lot, of research. For example, it has not been "proven" that lesions or bright areas found by some studies to exist in greater numbers amongst divers versus control populations cause damage. Bone necrosis tends to be more an issue for people engaged in saturation diving and dives involving heavy exposures. Bone necrosis amongst the recreational community is infrequent.

Excess inert gas is eliminated by the circulatory/pulmonary systems over a short time due to pressure gradient. The long term problems mentioned aren't so much a problem from residual inert gas hanging around for days or weeks as they are from the initial insult.

For recreational divers, the problem with having it and not knowing is really better stated having it and avoiding treatment because you're not sure about the cause.

 

[dive_lover88]

For recreational divers, the problem with having it and not knowing is really better stated having it and avoiding treatment because you're not sure about the cause.

I thought that having treatment was a "better safe than sorry" option. Do you mean that seeking treatment for a diagnosis that is suspected and going into the chamber will potentially harm the person?

 

[seadoggirl]

Also while we are asking question about DCS. Are there common prescription drugs or even over the counter drugs that would put you in higher risk for DCS? I'm writing a book and my villian wants to kill a diver and make it look like an DCS accident.

 

[DocVikingo]

Also while we are asking question about DCS. Are there common prescription drugs or even over the counter drugs that would put you in higher risk for DCS? I'm writing a book and my villian (sic) wants to kill a diver and make it look like an (sic) DCS accident.

Hi seadoggirl,

Sure there are. Dehydration predisposes to DCS and drugs which contribute to dehydration include certain antihistamines, decongestants, diuretics, anti-asthmatics, antibiotics, alcohols, Vit D and its analogs, among many others.

However, given that DCS (decompression sickness) by itself is almost never fatal, this would be an extremely poor, and even silly, way to try to off some one. Even with DCI (decompression illness) involving AGE (arterial gas embolism), a far more serious condition, the fatality rate in recreational divers is less than 1 in 100,000 dives.

There also is the issue of autopsy, where most of the compounds that might contribute to DCS would show up in the toxicology results.

Since you have freedom to script the story within sensible bounds, perhaps you could get around the autopsy issue. Then you could get into some really effective drugs, such as a massive overdose of an anticoagulant (e.g., warfarin) which could seriously predispose the diver to death simply from bleeding-related processes caused by normal equalization techniques. This could be given orally without the individual knowing.

Or, if necropsy is unavoidable, something like succinylcholine might be a good choice as it's absolutely fatal given in high enough dose and typically becomes pretty much undetectable if not ID'd relatively rapidly. Problem with it is it must given by injection and has a very rapid onset. Maybe a villain could hit the diver with it u/w? Or, there are certain synthetic compounds designed to circumvent federal and state laws governing opiates and cocaine that have lethal doses so small as to be often undetectable.

You'll need to do some homework, but this should get you started.

Best of luck,

DocVikingo

 

[Kendall Raine]

I thought that having treatment was a "better safe than sorry" option. Do you mean that seeking treatment for a diagnosis that is suspected and going into the chamber will potentially harm the person?

No. That's not what I meant. In most circumstances getting pressed when DCS is suspected, but not certain, is the right way to go. That's not always true; however. There may be circumstances where getting in a chamber makes treating other known complications (e. g. heart attack) more difficult. In general, getting in the chamber is the safer route.

I was trying to draw a distinction between having symptoms and deciding they're not DCS related (rightly or wrongly) and not having frank symptoms at all. I thought you were asking whether someone can have symptoms and not admit, or realize, they are DCS related.

 

[TSandM]

This is actually a question that comes up from time to time. Diving can be strenuous, and boats bite, and tanks are heavy and hard. It's not unusual to have some aches and pains after diving (I stood up FAR too long with my doubles on yesterday) and often, particularly with new divers, the question is whether those pains are DCS or whether they're just normal exertion or injury-related. To assess that, one has to take into consideration a lot of other data: Profiles, personal past history (for me, for example, it's pretty usual to have pain in my trapezius muscles if I've walked very far in my gear), recent diving history, high-risk factors. Even so, there can be a gray zone where it isn't clear to anybody what's going on.

If you are asking about DCS without ANY symptoms, that's an oxymoron, because by definition, DCS is symptomatic. However, we know many divers have bubbles present in the bloodstream after diving without having any identifiable symptoms at all. So bubbling and DCS are not equivalent at all.

 

[Dr Deco]

Hello dive lover88:

Unrecognized DCS

DCS can be present but the diver does not recognize it. As others mentioned, it is sometimes thought to be just a sore elbow, or possibly a cold or the flu. When a diver is unable to stand, then they begin to get very suspicious.

DCS is not an all-or-nothing event. Depending on the amount of free gas present, the signs and symptoms can be very mild or quite severe. This is related to the dive and the dose of nitrogen absorbed by the diver. Mild DCS is not easy to diagnose, and it is best determined by a “test of pressure.” This is recompression to see if the problem abates with pressure. Some divers believe that they will be writhing in pain if they have DCS. This is not true; most of the time it is mild in recreational divers.

Circulating Nitrogen :huh:

Gases are exchanged very rapidly in the lung capillaries. Any excess nitrogen present in venous blood will be eliminated in the lungs and not be carried over to the arterial system. There is therefore not long-term effect of “excess arterial nitrogen.”

Dr Deco :doctor:

 

[Dr Deco]

Hello seadoggirl:

Death by DCS :shakehead

Frankly, mild forms of DCS (“the bends”) are not fatal. Additionally, they have a variable response for each “dose” of dissolved nitrogen. Death can really only result from a massive production of internal gas bubbles such that one gets either arterial gas bubbles or a blockage of the heart when it fills with foam.

[1] Recreational divers would not find normally themselves in such a situation. In “The Last Dive,” the two divers were very deep on air, became trapped/lost in a wreck, and surfaced without adequate decompression. They died. If you could “trap” your deep-diving victim in some manner and then cause him to ascend without possibility of adequate decompression, he would be in a serious amount of hurt.

[2] A diver needing to decompress with extra cylinders suspended in the water at depth would likewise be in trouble if the cylinders “mysteriously” were missing when he began the ascent to his deep deco stops.

[3] Most divers die by drowning, but this is boring in a novel. Closed circuit rebreathers have their fair share of fatalities. Arranging for a failure of the oxygen sensor would prove to be devastating.

[4] Carbon monoxide occasionally enters the compressed gas mix and often with fatal results. As long as the victim was not breathing the same gas as all the others on the boat, this is a possible scenario.

Dr Deco :doctor:

 

[Couv]

My vote is a combination of Dr. Deco's #3 and #4 above...or sort of anyway. Give the victim too much O2 for his depth and a "faulty" O2 sensor. "But he mixed his gas himself, Inspector Clouseau"

...CO tox was done in "Coma" already.